1. Field of the Invention
The present invention relates to plate joints for joining plates together, and, more particularly, to parts fixtures including such plate joints.
2. Description of the Related Art
A parts fixture is typically used for holding parts during processing of the parts in an industrial process (with the phrase “industrial process” broadly defined herein to include any type of manufacturing or subsequent processing of parts). One such industrial process is thermally treating metal parts to obtain desired metallurgical properties. The thermal (or heat) treating process can occur onsite at a manufacturer, or the parts may be shipped to an offsite location for heat treatment. The parts to be heat treated are placed into the fixture and the loaded fixture is placed into an oven, vat, tank, etc. during the heat treating process.
A parts fixture as described above may be made in a multi-layer configuration, with parts to be treated being placed on each different layer, and the entire multi-layer fixture then processed for heat treatment of the retained parts. Such heat treatment occurs at elevated temperatures; and thus it is desirable to construct the fixture from a material which does not physically deteriorate, is dimensionally stability, and retains the original shape during thermal expansion and contraction.
In order to load and unload a multi-layer parts fixture as described above, it is sometimes necessary to assemble and disassemble the parts fixture for each load of parts. As the components making up the fixture are repeatedly assembled and disassembled, they may become worn over time, which may lead to changes in the dimensions and/or shape of the parts fixture. If the parts are loaded on top of each layer, the upper surface of the layer may not be flat, which can then lead to distortion of the parts during the heat treating process.
What is needed in the art is a joint for plates, e.g., in a parts fixture, which is robust and maintains dimensional and structural integrity.